Code 5 Lead is 2.24mm thick (a 24% increase over code 4 lead) and weighs 25.40kg/m2 (Thickness to BS EN12588 tolerances of +/- 5%)
As a result, code 5 lead can be used in every aspect of pitched roofing for sheltered applications and can be used for severe weather exposure for everything but flat roofing, parapet, box and tapered valley gutters. For vertical cladding, dormer roofs and cheeks, chimney, hip, ridge, apron or cover flashings you can safely use code 5 lead
As with code 4 lead, when the application is exposed to more severe weather and you are using lead for parapet, box or taper gutters, or if you are working on a historical or listed building (such as a church roof) the thicker gauges of lead are suggested.
Code 5 lead is appropriate on historical or listed buildings for uses such as chimney flashings or lead slates
The increased thickness also means that, like code 4 lead, code 5 lead has increased resistance to thermal movement and therefore the maximum length of flashing can be increased by 50% over code 3 lead to 1.5metres. It isn’t advisable to use any flashing in longer than 1.5m lengths.
It is always worth remembering that when chasing out brick or stonework, you should avoid pointing with mortar and instead use a lead sealant that allows for thermal expansion and contraction
JJ Roofing Supplies standard roll lengths of 3 and 6 metres will therefore give you either 2 or 4 lead flashing strips that will help waterproof your roof for generations.